Engineering Commons^™

Comparing The Performance Of Different Missing Data Imputation Approaches In Discrete Outcome Modeling, Md Istiak Jahan, Tanmoy Bhowmik, Lauren Hoover, Naveen Eluru

Civil and Environmental Engineering Faculty Publications and Presentations

Although several approaches exist for data imputation, these approaches are not commonly applied in transportation. The current paper is geared toward assisting transportation researchers and practitioners in developing models using datasets with missing data. The study begins with a data simulation exercise evaluating different solutions implemented for missing data. The dimensions considered in our analysis include: the nature of independent variables, different types of missing variables, different shares of missing values, multiple data sample sizes, and evaluation of single imputation (SI), multiple imputation (MI) and complete case data (CCD) approach. The comparison is conducted by adopting the appropriate inference process …

Spatio-Temporal Changes In The Gravity And Post-Mining Seismic Activity In Abandoned Deep Coal Mine Kazimierz-Juliusz During Flooding, Andrzej Kotyrba, Łukasz Kortas, Sławomir Siwek

Journal of Sustainable Mining

The flooding of an underground hard coal mine, resulting in the filling of post-mining voids (workings and goafs) and the repeated saturation of pore and interstitial spaces of the adjacent rock with water, change the mass and its distribution in the near-surface part of the earth’s crust. This process is slow and lasts many years. As a result, the local gravity field undergoes dynamic changes. It depends on the surface morphology and the density of geological strata, which is related to their water content. Changes in the local gravity field can be monitored by periodic gravity surveys performed in the …

Vibration Analysis And Condition Monitoring For Cement Mill (Case Of Hamma Bouziane-Constantine Cement Plant), Linda Bouyaya

Emirates Journal for Engineering Research

Monitoring and diagnosing damage in dynamic machinery is a growing area of interest in the cement industry. Indeed, industrial equipment is disrupted throughout its operation by malfunctions; especially in old age; which reduces their operating costs and availability. Therefore, the detection and identification of faults in industrial systems - diagnosis - is of capital importance for their operation and a major challenge for modern industry. Among the most used diagnostic techniques, we find spectral analysis, a condition-based maintenance tool, which is used to study the vibration signals of dynamic machines.

In this context, the objective of this work is the …

Multiphysics Simulation Of Biochar Adsorption Rates, Joseph Salerno

Graduate Theses & Non-Theses

An accepted carbon capture and sequestration (CCS) method to remove carbon dioxide from the atmosphere is via adsorption onto biochar. While the characteristics of the char are important and greatly impact the adsorption of CO2 molecules, the conditions in which the adsorption occurs are equally critical. Factors such as char particle size and quantity, environmental temperature and pressure, as well as outside driving mechanisms such as vibration frequency, driving force, and flow rates play an impactful role on how the char adsorbs CO2 particles. These factors and their effects will be studied in multiphysics simulations performed using methods that work …

Design Of A Semi-Continuous Bio-Oil Upgradation Process Using Iron/Bone-Char Catalysts, Kelli Thomas

Graduate Theses & Non-Theses

• 07Bio-oil is a pyrolysis byproduct that consists of heavily oxygenated organic fractions with low caloric values. There are very few industrial-sized facilities that can process bio-oil into useful hydrocarbons comparable to petroleum products. With the increase in biochar production for remediation efforts and forest clean-up, there is a demand for portable, small-scale refineries that do not require extensive process and safety equipment to convert byproducts into usable fuels. Refining bio-oil via atmospheric hydrodeoxygenation (HDO), the removal of the oxygenated functional groups under an unpressurized hydrogenated atmosphere, results in the upgradation of the heavy hydrocarbons within the bio-oil. This process is …

Process Intensification For Carbon Sequestration By Resonant Vibratory Mixing, Amirhosein Riahi

Graduate Theses & Non-Theses

Due to the excessive consumption of fossil fuels, which leads to significant greenhouse gas emissions and rapid climate change, it is crucial to develop various Carbon Capture and Sequestration strategies. CO₂ sequestration in solid, porous adsorbents like low-cost biochar emerges as a promising method to achieve this goal. However, slow adsorption kinetics are one of the issues that limit the widespread use of biochar. While the characteristics of biochar are important and impact CO₂ adsorption, the conditions under which adsorption occurs are equally critical.

In this work, a novel process intensification strategy, namely Low-Frequency High Amplitude resonant vibratory …

Stability, Mechanical Properties, And High-Pressure Structural Modifications Of Some Industrially Relevant Metallic Glasses, Alexander George

Graduate Theses & Non-Theses

Metallic glasses are metal-based alloys that have an amorphous structure and glass transition behavior as a result of being cooled rapidly enough to suppress crystal nucleation and growth[1]. Metallic glasses have been formed with two to eight constituents[2][3][4]; however, the most stable glass-forming systems typically contain four or more elements. With few exceptions, metallic glass-forming alloys are extremely unstable, requiring cooling rates on the order of 10⁸-10^-2 K/s to form a glassy sample. This instability translates to reheating, where onset crystallization temperatures infrequently exceed the glass transition by more than 100K. Strong glass-forming ability typically occurs over …

Mechanical Characterization Of Polymer Composites Embedded With Aramid Nanofiber, Evan Griffiths

Graduate Theses & Non-Theses

Self-healing materials are repairable and extend product lifetimes but are limited in application due to their mechanical properties such as low yield strength. Here, the mechanical properties of an elastomeric polymer composite containing aramid nanofiber are examined. These studies provided an economically feasible foundation to understand the doping concentration and resultant mechanical properties that would result should aramid nanofibers be used to reinforce a self-healing polymer that requires complex synthesis methods and expensive reactants. The elastomeric polymer used was polycaprolactone containing various weight percent aramid nanofiber. Quasi-static mechanical testing of these samples was performed following ASTM standardized tests for tension, …

Solar Process Heat Pyrolysis, Maxwell Triepke

Graduate Theses & Non-Theses

Solar process heat pyrolysis mobilizes the production of biochar via selective solar absorbance. Mobilization allows for the production of pyrolysis products at the location of the biomass source while eliminating the need for infrastructural power to operate the reactor. Traditionally, the implementation of economies of scale has led to large, permanent biochar production facilities; however, biochar feedstock is often in remote locations or stockpiled temporarily in mill/forestry operation locations. Modular reactors are important to eliminate feedstock location, transportation, and variability limitations. Previous work at Montana Technological University’s CHAR Laboratory has developed two lab scale modular, both tethered to infrastructural power. …

A Methodology For Evaluating And Comparing Unmanned Inspection Platforms In Underground And Indoor Environments, Sydney Shockley

Graduate Theses & Non-Theses

This report summarizes a research project focused on development of a methodology for evaluating the performance of various unmanned aerial vehicles (UAVs, commonly referred to as drones) and robotic platforms in GPS-denied environments, highlighting a clear stratification based on technological sophistication and design intent. A series of flight trials were designed and implemented in various environments including indoor spaces with various geometries and obstacles, and an underground mine. These trials examined signal range from the unmanned platform to the controller, the ability to navigate through confined spaces and obstacles, the overall ease-of-use and responsiveness of controls, as well as specialized …

Computational Fluid Dynamics Modeling Of 12.25” Horizontal Wellbores To Identify The Effects Of Pipe Rotation On Cuttings Transport Efficiency, David Rathgeber

Graduate Theses & Non-Theses

As global demand for oil and gas continues to rise alongside pressures to curb climate change, Exploration and Production (E&P) companies look to reduce their surface footprint and increase drilling efficiency through longer horizontal well drilling. In addition, the depletion of conventional reservoirs is causing E&P companies to target more difficult reservoirs, often miles offshore (Gupta et al., 2014; Meader et al., 2000a). The increased horizontal reach of these wells often leads to increased challenges in adequate hole cleaning during drilling operations. Efficient hole cleaning becomes a greater challenge in high-angle wells, with gravitational forces causing pipe eccentricity, flow channeling, …

Investigating The Production Of Af96 Steel Alloy By Additive Manufacturing Using Dry Metal Alloying, John Paul Osabutey

Graduate Theses & Non-Theses

The design of new alloys specifically for metal additive manufacturing (AM) is an emerging field of research. At present, metal AM primarily utilizes pre-alloyed powders, which are costly and lack flexibility in varying chemical compositions. This study outlines the adaptation of rapid alloy development in laser powder bed fusion (L-PBF) using elemental and ferro-alloyed powder blends. This method enables a more agile and resource-efficient approach to designing and screening new alloys, allowing for the swift generation of alloys with diverse chemical compositions. This thesis investigates the development of AF96 steel alloy through the innovative approach of mixing different elemental powders, …

Error Detection & Correction, Robert J. Twiggs

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Professor Bob Twiggs on "Error Detection & Correction" from August 2, 2024.

Re-Architecting Space Systems: Infrastructure Changes Everything, Rick Fleeter

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Professor Rick Fleeter on "Re-Architecting Space Systems: Infrastructure Changes Everything" from

Subspace Decomposition Of Linear Secrecy Codes, David Robert Joseph Hunn

Theses and Dissertations

We introduce a new method for the study of linear codes, termed subspace decomposition, which provides new insights into code structure and performance. Briefly, subspace decomposition comprises the evaluation of complex properties of a linear code by evaluating simple properties of its constituent subspaces. We find that this technique has application to a number of problems in coding theory. When applied to the problem of evaluating the performance of secrecy codes, subspace decomposition provides an efficient method for computing the equivocation of coset codes over the binary erasure wiretap channel. It is also especially efficient in computing the chi squared …

Boiling Crisis Is A Consequence Of Thermal Runaway In The Substrate Due To Degradation Of Nucleate Boiling Heat Transfer, Manohar Bongarala, Justin A. Weibel, Suresh V. Garimella

CTRC Research Publications

Chaotic bubble interactions during vigorous boiling have foiled attempts at an accurate mechanistic understanding of this important industrial transport process. Prediction of the boiling crisis (dryout) that occurs due to the spontaneous merger of bubbles into an insulating vapor film at critical heat flux remains an unsolved challenge. This work diagnoses the dryout process using synchronized high-resolution spatiotemporal heat flux and phase data, obtained via through-substrate infrared and visual inspection. We examine prevailing theories for the boiling crisis and provide evidence to rule out all but one. The boiling crisis is found to be a consequence of a peak in …

The Shoulder Effect In The Stagnation Zone For Temperature-Controlled Jet Impingement Transition Boiling Of Submerged Dielectric Fluid, Tyler P. Stamps, Justin A. Weibel

CTRC Research Publications

Two-phase jet impingement is capable of high heat transfer coefficients and high boiling critical heat flux (CHF) limits, making it a suitable technology for electronics immersion cooling applications. Previous studies have focused on the heat-flux-controlled nucleate boiling performance of an impingement jet up to the CHF. Exploration of other boiling regimes that occur under temperature-controlled surfaces is of equal fundamental importance. It has been shown for free jets that a high and consistent heat flux can be dissipated over a wide range of surface superheats in the transition boiling regime when the surface is temperature-controlled. This so-called “shoulder effect”, or …

Comm-Modulation & Data Transmission Errors, Robert J. Twiggs

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Professor Bob Twiggs on "Comm-Modulation & Data Transmission Errors" from August 2, 2024.

Evaluating The Role Of Data Enrichment Approaches Towards Rare Event Analysis In Manufacturing, Chathurangi Shyalika, Ruwan Wickramarachchi, Fadi El Kalach, Ramy Harik, Amit P. Sheth

Publications

Rare events are occurrences that take place with a significantly lower frequency than more common, regular events. These events can be categorized into distinct categories, from frequently rare to extremely rare, based on factors like the distribution of data and significant differences in rarity levels. In manufacturing domains, predicting such events is particularly important, as they lead to unplanned downtime, a shortening of equipment lifespans, and high energy consumption. Usually, the rarity of events is inversely correlated with the maturity of a manufacturing industry. Typically, the rarity of events affects the multivariate data generated within a manufacturing process to be …

Synthesis Of Uv-Blocking Titanium Oxide Films Via Remote-Type Atmospheric Pressure Plasma Cvd, Hayate Endo, Akira Shirakura, Shinya Kudo, Tetsuya Suzuki

Journal of Applied Packaging Research

This study aims to enhance UV resistance in plastics, focusing on polycarbonate (PC) and polypropylene (PP) commonly used in reuseable packaging. Traditional organic UV absorbers face safety and cost challenges, prompting our investigation into alternative methods. We utilized chemical vapor deposition (CVD), specifically Atmospheric Pressure Plasma Enhanced CVD (AP-PE-CVD), to apply titanium oxide (TiO₂) thin films. This innovative approach, using a remote-type AP-PE-CVD technique, enables coating on complex surfaces and 3D objects. The produced TiO2 films, containing over 20% titanium, showed a UV transmittance of 14.5% at 310 nm and effective UV blocking starting at 372 nm. The …

Development And Structural Origin Of Stretchable Semiconducting Polymers And Composites, Yunfei Wang

Dissertations

Stretchable semiconductors are pivotal in advancing wearable and implantable electronics, with those boasting both high stretchability and self-healing capabilities being especially significant for a myriad of wearable applications. In this dissertation, we developed an extremely soft, highly stretchable, and self-healing elastomer based on H-bonding crosslinked amide-functionalized polyisobutylene (PIB-amide). When blended with a high-performance conjugated diketopyrrolopyrrole (DPP-T) polymer, the composite exhibits unprecedented stretchability, exceptionally low elastic modulus, and an innate ability to self-heal at room temperature.

The morphology of conjugated polymer/elastomer semiconducting composites have significant impacts on electrical and mechanical properties Further investigations focused on manipulating the phase separation size in …

Effect Of Absorption Kinetics Of Superabsorbent Polymers On Printability And Interlayer Bond Of 3d Printing Concrete, Yu Cun Gu, Shuyi Zheng, Hongyan Ma, Wu Jian Long, Kamal H. Khayat

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This study examines the effect of the material characteristics of superabsorbent polymers (SAPs) on the printability and interlayer bond strength of 3D printing concrete. Three types of SAP, including two acrylamide-co-acrylic polymers with coarse and fine particle sizes (S1 and S2) and an acrylic copolymer (S3), were employed. The investigated mortar mixtures had a fixed initial mini-slump flow of 195 ± 10 mm and yield stress of 290 ± 25 Pa. The fluidity of SAP-incorporated mortars was maintained by either adjusting the superplasticizer dosage or increasing the water content. Test results indicate that particle flocculation is dependent on SAP absorption …

Extrudability Window And Offline Test Methods To Predict Buildability Of 3d Printing Concrete, Yu Cun Gu, Kamal H. Khayat

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This Study Investigates the Effect of Thixotropy and Stiffness Evolution on the Extrudability and Buildability of 3D Printing Concrete. Different Types of Supplementary Cementitious Materials and Limestone Filler Were Used to Prepare Mortars with Varying Levels of Thixotropy and Early-Age Stiffness. Mixtures with Yield Stress and Flocculation (Τfloc) of 180–400 and 420–950 Pa, Respectively, Exhibited Adequate Extrudability Without Plastic Collapse. the Printing Was Completed 8–15 Min after Mixing at a Vertical Build-Up Rate of 138 Mm/min. Several Process Parameters, Including Rest Time to Secure a Penetration Resistance of 150 KPa (T150) and Penetration Resistance at Various Rest Times Were Developed …

The Effectiveness Of Waste Tire Pyrolysis Oils (Wtpos) As Rejuvenating Agents For Asphalt Materials, Ahmed S. El-Ashwah, Magdy Abdelrahman

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The continuous increase in solid waste materials, such as waste tires, underscores the critical importance of recycling them to mitigate environmental impact and promote sustainable resource management. This research study evaluated the effectiveness of utilizing waste tire pyrolysis oils (WTPOs) as recycling agents for asphalt materials. The chemical composition and thermal behavior of WTPO were analyzed using Fourier transform infrared (FT-IR) spectroscopy and thermogravimetric analysis (TGA). Mechanically, the prepared WTPO binders were assessed by measuring dynamic viscosity and changes in high- and intermediate-temperature performance grades. Additionally, the cracking susceptibility of the binders was evaluated using the Glover-Rowe (G-R) parameter. The …

Evaluation Of The Alveolar Crest And Cemento-Enamel Junction In Periodontitis Using Object Detection On Periapical Radiographs, Tai Jung Lin, Yi Cheng Mao, Yuan Jin Lin, Chin Hao Liang, Yi Qing He, Yun Chen Hsu, Shih Lun Chen, Tsung Yi Chen, Chiung An Chen, Kuo Chen Li, Patricia Angela R. Abu

Ateneo Laboratory for Intelligent Visual Environments

The severity of periodontitis can be analyzed by calculating the loss of alveolar crest (ALC) level and the level of bone loss between the tooth’s bone and the cemento-enamel junction (CEJ). However, dentists need to manually mark symptoms on periapical radiographs (PAs) to assess bone loss, a process that is both time-consuming and prone to errors. This study proposes the following new method that contributes to the evaluation of disease and reduces errors. Firstly, innovative periodontitis image enhancement methods are employed to improve PA image quality. Subsequently, single teeth can be accurately extracted from PA images by object detection with …

Settingsorder Article Reprints Open Accessarticle A Model To Account For The Effects Of Load Ratio And Hydrogen Pressure On The Fatigue Crack Growth Behavior Of Pressure Vessel Steels, Ashok Saxena, Kip O. Findley

Mechanical Engineering Faculty Publications and Presentations

A phenomenological model for estimating the effects of load ratio R and hydrogen pressure P_H2 on the hydrogen-assisted fatigue crack growth rate (HA-FCGR) behavior in the transient and steady-state regimes of pressure vessel steels is described. The "transient regime" is identified with crack growth within a severely embrittled zone of intense plasticity at the crack tip. The "steady-state" behavior is associated with the crack growing into a region of comparatively lower hydrogen concentration located further away from the crack tip. The model treats the effects of R and P_H2 as being functionally separable. In the transient …

Quantifying The Impact Of Technology Utilization On Schedule And Cost Performance In Construction Projects, Fareed Salih, Islam H. El-Adaway

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

There Has Been a Plethora of Research on the Performance of Schedule and Cost in Construction Projects. However, Current Research Falls Short in Investigating the Combined Contribution of Different Construction Technologies on Project Performance Metrics. Specifically, None of the Previous Efforts Have Used Integrated Earned Value Management (EVM) Parameters and Utilized Construction Technologies to Assess Project Schedule and Cost Performance. This Paper Fills This Knowledge Gap. to This End, a Multistep Research Methodology Was Employed to (1) Explore the Utilization Ratings of 13 Construction Technologies based on Data Collected from 52 Industry Experts; (2) Rank These Technologies in Terms of …

Surface Patterning On Zirconia Dental Implants Via Laser-Induced Shockwave Imprinting, Inomjon Majidov

Masters Theses & Specialist Projects

Zirconia is rapidly becoming a preferred alternative to titanium in dental applications, primarily due to its aesthetic resemblance to natural teeth. This material’s tooth-like color avoids the aesthetic issues associated with the grey metal tint of titanium implants. Additionally, zirconia is hypoallergenic, making it an ideal choice for patients with metal sensitivities or allergies. Despite these advantages, zirconia generally exhibits lower biocompatibility and osseointegration compared to titanium implants. This study investigates laser-assisted, controlled imprinting technique on zirconia surfaces to enhance these properties. Our research used zirconia pellets, produced from powdered monoclinic zirconia pressed in a pellet press machine. Two methods …

Quantifying Lock Criticality For Inland Waterway Navigation Using An Agent-Based Simulation, Ashwin Narayan

Industrial Engineering Undergraduate Honors Theses

Inland waterway travel has tremendous potential to improve multimodal transportation in the United States due to its environment-friendly and safe nature. Waterway travel has proven to be much cheaper per ton-mile and more fuel efficient than trucks. Millions of dollars have recently been invested in inland waterway networks to facilitate travel. The waterway infrastructure must be resilient to enable efficient waterway travel and prevent unnecessary delays. Locks, an important component of waterway infrastructure, enable vessels to travel between waterways of varying depths and must be maintained consistently to avoid unexpected failures. However, with limited resources, it is difficult to preserve …

Thrombogenicity Of Biodegradable Metals, D. E.J. Anderson, H. H. Le, H. Vu, J. Johnson, J. E. Aslan, J. Goldman, M. T. Hinds

Michigan Tech Publications

Biodegradable metals offer a promising means to ameliorate many of the long-term risks associated with vascular devices made of conventional biostable stent metals. While numerous biodegradable metal alloys have been developed and characterized in animal models, knowledge of their blood reactivity and thrombogenicity remains unknown. Metal hemocompatibility is particularly valuable because current generation drug-eluting stents pose a significant long-term thrombosis risk. In this study, four pure metals, widely used as degradable base materials (Fe, Zn, Mg, and Mo), and three alloys commonly used in cardiovascular devices [NiTi, CoCr, and stainless steel (SS)] were evaluated. This work examined how each of …